It is widely recognized that the human body and its associated physiology are both complex and fragile in nature. Throughout a normal human lifespan, a person will suffer from various physiological “malfunctions” mostly in the form of aging and/or disease, which reduce the quality of life, and in certain severe circumstances, may result in death. Some of these conditions are gender specific or gender selective due to the various differences in male and female anatomy and physiology. For example, uterine, ovarian and cervical cancer are female specific, whereas conditions such as prostate and testicular maladies are male specific.
One category of afflictions that specifically affect women is generally known as ‘Female Sexual Disorders.’ These disorders are defined in The Diagnostic and Statistical Manual of Mental Disorders (“DSM”), and include the following three categories: (1) Genitopelvic pain/penetration disorder; (2) Sexual interest/arousal disorder; and (3) Female orgasmic disorder. All of these afflictions are common and known to significantly reduce the quality of life for millions of women and their sexual partners.
In the most current version of DSM, (DSM-V), older terminologies, both Hypoactive Sexual Desire Disorder (HSDD) and Female Arousal Disorder were merged into a single category of female sexual disorder now called Sexual Interest/Arousal Disorder (SIAD). Similarly, the formerly separate dyspareunia and vaginismus disorders are now collectively called Genitopelvic Pain/Penetration Disorder (GPPD). The terminology Female Orgasmic Disorder (FOD) remains unchanged.
GPPD is an underreported condition and can occur at any time in a woman's life cycle. 50% of postmenopausal women suffer from a degree of genital pain/penetration disorder, and 15% of all women will experience vestibulodynia, or provoked vulvar pain, at some point in their lifetime. The prevalence of sexual interest/arousal disorder (SIAD) varies, but studies indicate a range from about 26.7% of premenopausal women to about 52.4% of naturally post-menopausal women. Lastly, 4-10% of women do not have orgasms and up to 26% of women report having at least some difficulty with having an orgasm.
The DSM-V defines genitopelvic pain/penetration disorder, (GPPD) as difficulty in vaginal penetration, marked vulvovaginal or pelvic pain during penetration, or attempt at penetration (dyspareunia), fear or anxiety about pain in anticipation of, during, or after penetration, and tightening or tensing of pelvic floor muscles during attempted penetration (vaginismus).
For many women, however, pain may occur outside the context of penetration or sexual intercourse. For example, pain or discomfort may occur during any manipulation of their external genitalia (a condition known as vulvodynia). Such pain or discomfort may be due to Vulvovaginal atrophy (VVA), including thinning of the vulvovaginal epithelium and a lack of lubrication and/or may be characterized as vulvodynia.
Vulvar pain is also a frequently occurring problem that affects both pre and post-menopausal women. Generally speaking, vulvodynia may present as more diffuse, constant vulvar pain, exhibiting a general sensation of burning or rawness in affected areas. Localized vulvodynia also known as vestibulodynia is pain around the opening of the vagina, the vulvar vestibule, most commonly found around the posterior hymenal ring between 4 and 8 o'clock, a region sometimes referred to by medical practitioners as the “posterior forchette.” This is the most common cause of vulvar pain and the leading cause of dyspareunia in women under the age of 50.
This condition may manifest itself as primary vestibulodynia (i.e. pain with first attempted tampon and/or intercourse) or secondary vestibulodynia (i.e. development of vulvar pain following previously painless tampon use and/or intercourse). Conservative estimates indicate that at least 16% of women in the United States (˜14 million women) have experienced some form of chronic vulvar pain. This pain and discomfort seriously impacts and degrades the quality of life. Women suffering from this condition are in need of a clinically-proven, effective treatment, as they regularly self-treat symptoms, wasting both time and money on ineffective treatments. Vulvologists from around the world, including The International Society for the Study of Vulvovaginal Disease, and practitioners from multiple professions including: medicine, psychology, physical therapy and nursing have been unable to find an effective treatment for vestibulodynia and/or chronic vulvar pain, i.e., vulvodynia. To date, there has been no effective treatment for this life-altering vulvar pain.
Genitopelvic pain in general tends to be underdiagnosed because many women are either not asked about it in connection with regular medical exams or are uncomfortable discussing it with their healthcare professional. Furthermore, genitopelvic pain/penetration disorder (GPPD) frequently becomes the cause (or a significant contributing factor) in the manifestation of sexual interest/arousal disorder (SIAD) because the anticipation of pain during sexual encounters may, over time, form a negative cognitive response that inhibits sexual interest, desire and/or arousal.
One cause of genital pain/penetration disorder (GPPD) is Vulvovaginal atrophy (VVA). Symptoms may include difficulty or inability to allow penetration, painful intercourse (dyspareunia), irritation, soreness, pain of the external genitalia, specifically of the vulva (vulvodynia), and dryness or decrease in lubrication from loss of mucous secretion. These symptoms exert a negative impact on the quality of life of up to 50% of all postmenopausal women.
Clinical diagnostic indicators of VVA include elevation of vaginal pH and a decrease in the vaginal maturation index. The low glycogen content of the thinned epithelium leads to a reduction in lactic acid production by lactobacilli bacteria, thereby increasing vaginal pH. A vaginal pH of greater than 5, in the absence of other causes, such as infection or semen from recent intercourse, is typically considered an indicator of vaginal atrophy due to lack of estrogen.
Maturation index is a term used to indicate the percentage of vaginal cell types as determined from a cytological exam of surface cells from the upper one third of the vagina. It is typically expressed as percentages of each of three cell types (i.e., parabasal, intermediate and superficial cells) found on a wet prep exam. Premenopausal women with adequate estrogen levels have a maturation index of 40% to 70% intermediate cells, 30% to 60% superficial cells, and substantially no parabasal cells (<1%). In vaginal atrophy, there is an increase in the parabasal cell population and a corresponding decrease in superficial cells, evidence of the thinning of the vaginal epithelium.
Currently, there are three types of treatments available to address the symptoms of Vulvovaginal Atrophy: 1) the topical or systemic use of exogenous estrogens, 2) The systemic use of a selective estrogen receptor modulator (“SERM”) and, 3) the topical use of external lubricants or moisturizers.
The lack of estrogen is believed to be responsible for some VVA symptoms in women. This estrogen deficiency may be due to age-related menopause, or iatrogenically induced menopause which is more likely the cause of estrogen deficiency in younger, pre-menopausal, women who are estrogen deficient. However, it is important to note that genital pain, involving both dyspareunia and vulvodynia, do occur in pre-menopausal women and/or in other women having essentially normal estrogen levels. Thus, not all genital pain/penetration disorders can be adequately addressed with exogenous estrogens.
Various forms of estrogens are currently available to treat women with VVA associated genital pain/penetration disorder. They include oral estrogens with or without progestins, topical estrogens as creams, suppositories or solid hormone releasing rings (Estring). Bioidentical estrogens are 17 beta-estradiol, estrone, and estriol. Sources of estrogen maybe synthetic, animal source, (Premarin), or plant based extracted from soy or yams. Regardless of the source, however, such compounds are all still estrogenic in their inherent effects, both beneficial and adverse, on estrogen sensitive target tissues.
As a result, many women either do not want or are unable to use oral or topical estrogens, which is the current standard therapy prescribed for treating symptoms of VVA. Despite being topical, estrogens applied locally to the vagina undesirably can and do cause statistically higher levels of plasma estradiol. There are significant risks to the use of both oral and topical estrogens in post-menopausal women with or without the adjunctive use of a progestin. The Women's Health Initiative (WHI) determined the following risks to be associated with estrogen use: 1) An increased risk of endometrial cancer in a woman with a uterus who uses unopposed estrogens; 2) An increased risk of stroke and deep venous thrombosis (“DVT”) in post-menopausal women using unopposed estrogens; 3) An increased risk of probable dementia in post-menopausal women using unopposed estrogens.
Further, a WHI study reported that women taking estrogen plus progestin had an increased risks of deep venous thrombosis (DVT), pulmonary embolism (PE), stroke and myocardial infarction (MI) in postmenopausal women. Additionally, an estrogen plus progestin ancillary study of the WHI reported an increased risk of developing probable dementia in postmenopausal women. The WHI estrogen plus progestin sub-study further demonstrated an increased risk of invasive breast cancer. Presently, there are no known safety studies to support the use of oral or topical vaginal estrogen in breast cancer survivors, and any estrogen use by breast cancer survivors is considered to be contraindicated by many health-care professionals.
Even while taking systemic (oral) estrogen, 10%-20% of women still suffer from certain residual VVA symptoms. Breast cancer treatment has been linked to an increase in the prevalence of VVA because the surgical, endocrine, and chemotherapeutic agents used in its treatment can cause or exacerbate VVA. As mentioned above, the use of locally applied estrogen treatment for this group of women remains controversial, and, at best, is only marginally effective.
Other currently available treatment options include the use of selective estrogen receptor modulators (SERMs), such Ospemifene (OSPHENA®), an FDA approved oral medication for moderate to severe dyspareunia (GPPD) associated with VVA due to menopause. Such SERMs act as a hormone by binding to the estrogen receptors Erα and ERβ, but bind more selectively to certain target organs such as the vagina, and thus produce less systemic estrogenic side effects compared to more non selective oral estrogens. Ospemifene, however, exerts a strong, nearly full estrogen agonist effect in the vaginal epithelium as evidenced by improvement of the vaginal maturation index and decreased vaginal pH. It is an oral medication with both systemic and local estrogenic effects that has to be taken indefinitely to maintain its therapeutic effects. Oral Ospemifene carries the risk of increased cardiovascular events such as deep venous thrombosis, stroke, myocardial infarction, thickening of the endometrium, endometrial polyps, breast tenderness, and breast lumps.
Finally, treatment options for VVA include the use of vaginal moisturizers and lubricants to provide temporary relief from vaginal dryness and dyspareunia by reducing friction. Such compounds, however, do nothing to restore the normal anatomy or function of the female genitalia; thus, they have no long-term therapeutic effects. These exogenous topically applied intravaginal therapeutics can be messy as they will leak out of the vagina when a woman is in the upright position, and are not produced by a woman's body in response to normal physiological responses to sexual stimulation. Vaginal estrogen therapy has proven more effective for VVA than all forms of non-hormonal therapy.
Another contributing cause of genital pain/penetration disorder (GPPD) is known as vestibulodynia, vulvodynia and/or vestibulitis. This affliction may be seen in up to 15% of all premenopausal women sometime in their lifetime. It is also a very common affliction of postmenopausal women unrelated to VVA.
Female vestibulodynia may be generally described as a disorder of unknown etiology where there is localized provoked vulvar pain upon penetration of the vagina. There is also tenderness to touch around the vaginal opening (vestibule) during normal self or partner's manual sexual contact or during a health professional's physical examination. The entire area around the vaginal introitus (vulvodynia) can be affected but the experienced discomfort or pain is most commonly pronounced in the localized area of the posterior forchette (vestibulodynia). The affected tissue in the vestibule has increased nerve endings and signs of inflammation and is typically painful. It occurs in women of all ages. It is estimated that approximately 15% of women (about 1 in 7) will experience this type of vulvar pain sometime in their lifetime. Vestibulodynia may lead to dyspareunia or painful intercourse and thus interfere with sexual function by causing pain in genitalia. Vestibulodynia is a challenging disorder and to date there is no definitive treatment for this condition despite a range of treatments, which include: oral tricyclics, neuromodulators (i.e., gabapentin), topical anesthetics, botulinum injections, intralesional corticosteroid injections, biofeedback, sexual therapy, psychotherapy, physical therapy, and surgery as a last resort in an attempt to remove the painful tissue. Women who have vestibulodynia often simultaneously suffer from sexual interest/arousal disorder (SIAD) and female orgasmic disorder (FOD) directly because of experiencing vestibulodynia, or provoked vulvar pain.
The two other disorders of female sexual dysfunction are: sexual interest/arousal disorder (SIAD) and female orgasmic disorder (FOD).
Sexual Interest/Arousal Disorder (“SIAD”) as specified in the DSM refers to “the persistent or recurrent inability to attain or to maintain sufficient sexual excitement, which causes personal distress.” In addition to absent or decreased sexual interest, including erotic thoughts or fantasies, there are four criteria that are taken into account to determine whether a woman suffers from SIAD. A woman has SIAD if she experiences personal distress caused by a decrease or lack of at least three of the following four criteria: 1) initiation of sexual activity or responsiveness to a partner's attempts to initiate it, 2) excitement and pleasure, 3) response to sexual cues, and 4) sensations during sexual activity, whether genital or non-genital. Again, three of the foregoing criteria are required for diagnosis. It may be expressed generally as lack of subjective excitement or lack of genital (lubrication/swelling) or other somatic responses.
The prevalence of Sexual Interest Arousal Disorder (SIAD), including low sexual desire, may range from about 26.7% of premenopausal women to 52.4% of naturally post-menopausal women. The disorder had no FDA-approved treatments (until August 2015 when Flibanserin, Addyi, was approved), and the FDA has recognized the condition as an area of unmet medical need.
Female orgasmic disorder, (FOD) as defined in the DSM, is the absence (anorgasmia), infrequency or delay of orgasm, and/or reduced intensity of said orgasm. Such orgasmic dysfunction may also occur when a woman has difficulty reaching orgasm, even when sexually aroused with sufficient sexual stimulation. Many women have difficulty reaching orgasm with a partner, or during masturbation, even after ample sexual stimulation. Female Orgasmic Disorder (FOD) affects approximately one in three women.
It can be difficult to determine the particular underlying cause of Female Orgasmic Disorder (FOD). Women may have difficulty reaching orgasm due to one or more physical, emotional, and/or psychological factors. Contributing factors include: older age, medical conditions, such as diabetes, a history of gynecological surgeries, such as a hysterectomy, the use of certain medications, particularly selective serotonin reuptake inhibitors (SSRIs), mental health conditions, such as depression or anxiety, stress, societal negative stereotypes of women's sexuality, lack of adequate or effective sexual stimulation, etc. Sometimes, a combination of these factors can make achieving an orgasm difficult or not possible.
The inability to orgasm can lead to distress, which may make it even more difficult to achieve orgasm in the future. The main symptom of orgasmic disorder is the inability to achieve sexual climax. Women with female orgasmic disorder (FOD) may have difficulty achieving orgasm during either sexual intercourse or during masturbation.
For many women, having unsatisfying orgasms, less intense orgasms, or taking longer than desirable to reach climax are common symptoms of FOD that lead to emotional distress.
The initial goal of therapy for female orgasmic disorder is to enable the patient to reach an orgasm as desired under any circumstance. Underlying medical etiologies must first be considered including antidepressant-induced anorgasmia, anorgasmia secondary to substance abuse, and underlying neurological disorders.
Evidence about the effectiveness of psychological therapies in successfully treating FOD is inconclusive. Testosterone in combination with estrogen has been tried, but to date no pharmacologic agents have proved to demonstrate long-term beneficial effects on orgasmic function in women with FOD, beyond a placebo effect. A Canadian company is working on a low-dose nasal testosterone gel treatment for female orgasmic disorder, FOD.
However, at present, no medication has been specifically approved by the US Food and Drug Administration (FDA) for the treatment of FOD. In addition, very little information is available about pharmacotherapy specifically targeting disorders of orgasm in women. The significant inherent risks of oral or topical hormonal therapy remain a concern.
Finally, over-the-counter (OTC) products (Zestra®) and nutritional supplements are marketed, but are ineffective in treating women with FOD. Thus, there is currently no safe or effective treatment for female orgasmic disorder (FOD) that enables an orgasm or enhances the intensity of said orgasm. Therefore, for the treatment of female orgasmic disorder (FOD), it is desirable to provide a therapeutic compound and associated treatment that is easy for the patient to use (e.g., a medication that can be applied to the affected area by the patient themselves) that shows significant improvement in orgasmic ease and intensity in a relatively short period of use and having no significant side-effects.
As discussed above, problem of SIAD encountered by many women reduces quality of life manifested as low female libido or sexual desire, and decreased or absent sexual arousal. In the past, treatments for low female libido have had little success. Some physicians have prescribed various forms of off-label testosterone preparations to increase libido with limited results. Testosterone, however, is not approved by the FDA for treating libido problems in women. Long-term safety data on testosterone therapy for postmenopausal women who have a history of breast or uterine cancer, or who have cardiovascular or liver disease, is lacking, and is being studied. Available data suggests there may be an increased risk of heart attacks, stroke, hair loss on scalp, hair growth on face, acne, heart disease, clitoralmegaly, risk of breast or uterine cancer through conversion of testosterone to estrogen, blood clots, deepening of voice, and fetal abnormalities (in pre-menopausal women).
Currently, there is no treatment for female SIAD. Thus, it desirable to provide a therapeutic compound and associated treatment that is easy for patients to use, that shows significant results in a relatively short period of time, and has no significant side-effects.
One attempt to create a safe and effective treatment for low female libido resulted in the development of the compound Flibanserin, by Sprout Pharmaceuticals, known by the tradename ADDYI, or more colloquially “The Pink Pill.”
Flibanserin, (BIMT 17 BS; 2H-benzimidazol-2-one, 1,3-dihydro-1-[2-[4-[3(tri-fluoromethyl) phenyl]-1-piperazinyl]ethyl]) is a non-hormonal, centrally acting molecule that acts as an agonist at postsynaptic 5-HT1A receptors and as an antagonist at 5-HT2A receptors.
Approved by the FDA in August 2015, Flibanserin is the first and only drug indicated for pre-menopausal women for SIAD related disorders (formerly termed hypoactive sexual desire disorder). During FDA evaluation, Flibanserin, was twice rejected because according to FDA reviewers: “Flibanserin has a challenging benefit/risk assessment.” This is due to its relative lack of efficacy for the intended indication as well as the prevalence of certain undesirable side effects. For example, from a median baseline of about 2-3 satisfying sexual events (“SSEs”) per month, Flibanserin resulted in a median placebo-corrected increase of only about 0.5-1.0 SSEs per month over a six month period. Moreover, this marginal benefit was seen in only 18% of women taking 100 mg daily of the systemic drug for a minimum of 28 days.
During trials, it was observed that the risks of sedation or hypotension-related adverse events are substantially higher with Flibanserin vs placebo (28.6% Flibanserin vs 9.4% placebo). Flibanserin acts on the central nervous system and must be taken continuously and indefinitely. Side effects of Flibanserin are significant and include hypotension, syncope and somnolence. The risk of such side effects is amplified by drug interactions with CYP3A4 inhibitors such as oral contraceptives or Fluconazole and with concomitant alcohol intake. The FDA concluded that the clinically significant pharmacodynamic interaction between Flibanserin and alcohol is challenging to mitigate, particularly because Flibanserin requires daily use and alcohol consumption, including excessive drinking, is not uncommon in many cultures and further common for those engaging in sexual activity. The combination of ethanol and Flibanserin resulted in concerning cases of hypotension and pre-syncope/syncope. In addition, Flibanserin trials were limited to generally healthy women who were not taking additional medication such as benzodiazepines, sleep aids, narcotics, or other medicines. As with many drug trials, Flibanserin trials were of short duration relative to the potential length of time that Flibanserin could be indicated. Further, it is noteworthy that Flibanserin demonstrated no therapeutic effect at all on Genitopelvic pain/penetration disorders (GPPD) including vestibulodynia and dyspareunia or on Female Orgasmic Disorder (FOD).
Thus, in view of the foregoing, there is currently a lack of safe efficacious treatments for Female Sexual Disorders including genitopelvic pain/penetration disorder (GPPD), sexual interest/arousal disorder (SIAD), and female orgasmic disorder (FOD).